Manufacture of articles from steel alloys



45 removing gases is notably greater than the efiect ever. y amount p to 45 Patented May 9, 1939 s UNITED STATES PATENT OFFICE v Q MANUFACTURE ozilggljlgms FROM Friedrich Karl Naumann, Essen, Germany, as-

signor to, Fried. Krupp Aktiengesellschaft, Essen-on-the-Ruhr, Germany N Drawing. Original application March 3, 1934, Serial No. 713,925. Divided and this applica-, tion September 13, 1937, Serial No. 163,618. In Germany March 20, 1933 6 Claims. (Cl. 'l5123) This application is a division, of my applicafrom steel alloys which contain at least one of tion serial Number 713,925, filed March 3, 1934. the elements of group V. of the periodic table This invention relates to the manufacture from which form carbides in the steel, viz. vanadium, steel alloys of articles which in their normal use columbium and tantalum. In the case of a steel are subjected to the attack of hydrogen at high alloy in which the element of group V. which 5 hydrogen partial pressures and high temperaforms carbides in the steel is vanadium according tures. The invention is particularly applicable to the invention, the vanadium content amounts to the manufacture of apparatus and parts thereto more than 0.3%

of whichare used in the destructive hydrogena- Test bars of a cross section of x 10 mm. m t1on of 011 and coal, or in the synthesis of ammade from steels of the following composition 10 moma, and w th which hydrogen or mixtures of 0.09% 0 39% si, 0.48% Mn, 0.62% V,

gases containing hydrogen come into contact at 8.3g? 8 2%? lfi kg? X high temperatures and pressures. 1 C, 2, Mn Ta It has already been proposed to manufacture 16 the parts exposed to pressure, of apparatus used in operating with hydrogen and gas mixtures containing hydrogen under pressure and at elevated after having been exposed in a high pressure tube during 100 hours to the attack of hydrogen under pressure of 300 at and at a temperature temperatures, from alloyed steels which contain of 6000 Showed loss of carbon thatflcould omium, tungsten, molybdenum or vanadium be detected analytically or metallographically.

and if desired nickel. Tests made with steel al- In contrast them" Steels the 2 loys containing vanadium, however, showed only 0.10% C. 0.3 0.51% Mn, 1.96% O a very slight increase of the resistance of the 811 21 81333;; 8 2232 1133 {4 5 alloys to the attack of hydrogen. A steel alloy,

for example, containing 0.25% C, 0.26% Si, 0.48% Mn, 2.08% Cr and 0.30% V has lost its carbon to afdtepgh of 3.8 mm when subjected to the action 0 y rogen for 59 hours at a temperature of 600 C. and a pressure of 300 at., whilst for example dmm Is to be observed It the vaPadmm content a Steel containing 0.23% C, 026% Si, 050% Mn amounts at least about to four times the carbon 1.97% Gr and 0.44% Mo under equal conditions 9 50 that qetermineq' quantity of carbon after 300 hours showed a depth of carbon re- 1s bound as vanadmm carblde' The maxlmum moval of 2.1 mm only. The influence of the V- reslstance to attapk of the gases above content on the resistance of the steel to carbon mentloned is obtamed; 1f the V content amounts removing gases thus was only small at any rate to at least about 5.6 times the C content, so that smaller than that of the molybdenum. It has the wh1e of the carbon 15 mum to the vanadlllm been found, however, that vanadium imparts to as the steel a very high resistance to the attack of carbon content of the alloys used accordcarbon removing gases, if added to the steel in mg to the invention Preferabb does not exceed higher percentages than it is usual f improving 1%. The vanadium content preferably amounts mechanical properties. of the steel. For, if so 170 not over ab ut 5%, but must be higher than 40 much vanadium is added to the steels, that the Also the content of columblum r a avanadium content amounts to at least four times 111m may amount to about The balance of the C-conterrt,- and in all cases, more than 0.3%, the alloy be Substantially iron W the normal its eflect on the resistance to the action of carbon contents of Mn. and Si. The latter content.

when treated in the same manner were seriously attacked already after 10 hours and had lost the carbon nearly completely after 100 hours.

A particularly favorable influence of the vana- Obtained by the additionof equal percentages Furthermore, in order to improve the mechaniof chromium, tungsten or molybdenum. Besides 031 Properties of the W alloys and their vanadium, also the remaining elements of group Si tance to scaling and corrosion. further alloy V. of the periodic table which form carbides in constituents may be added to the alloys used acthe steel, viz. columbium and tantalum, impart cording to the invention, such as silicon, 50 to the steel high resistance to the attack of hymanganese, nickel, cobalt, chromium, tungsten drogen and hydrogen containing gases that atand molybdenum. The total content of these tack and remove carbon. elements, separate or mixed, may amount to The present invention therefore consists in the about 30%. In general, however, a total content manufacture of articles of the class described of not more than 15% thereof is found satis- 55 use of steels according to the invention which contain carbon in an amount not exceeding 0.4%

vanadium, columbium or tantalum in an amount not exceeding 2%, molybdenum in an amount not exceeding 3%, with or without chromium in an amount not exceeding 10%. For apparatus for'the destructive hydrogenation of oil and coal as well as for the synthesis of ammonia the following steel alloys may, for example, be used:

1. A steel alloy containing about 0.10% C,

0.30% Si, 0.50% Mn, 0.80% V.

2. A steel alloy containing about 0.08% C,

0.30% Si, 0.50% Mn, 1.0% Cr, 0.50% V.

3. A steel alloy containing about 0.10% C, 1.5% Si, 0.50% Mn, 6.0% Cr, 0.4% M0, 0.6% V.

I claim:

1. Articles which in their normal use are sub jected to the attack of hydrogen at high hydrogen partial pressures and high temperatures, saidarticles being composed of a. steel alloy consisting of carbon not over 1%, over 0.3% and not over 5% of one or more elements selected from the group vanadium, columbium, tantalum; the remainder substantially iron with silicon not over about 1.5% and'a manganese content within the usual range for low alloy steels.

2. Articles which in their normal use are subjected to the attack of hydrogen at high hydrogen partial pressures and high temperatures, said articles being composed of a steel alloy consisting of carbon not over 1%; vanadium in an amount at least four times greater than the carbon content and not over 5%; the remainder substantially iron with silicon not over about 1.5%

- 0.3% and not over 5% 01' ma and a'manganese content within the usual range for low alloy steels.

3. Articles which in their normal use are subjected to the attack of hydrogen at high hydrogen partial pressures and high temperatures, said articles being composed of a steel alloy consisting of carbon not over 0.89%. vanadium in an amount at least 5.6 times greater than the carbon content and not over 5%; the remainder substantially iron with silicon not over about 1.5% and a manganese content within the usual range for low alloy steels.

4. Hydrogenating apparatus having its parts which are subjected to the attack of hydrogen at high pressure and temperature, composed of a steel alloy containing carbon not over 1%, over 0.3% and not over 5% of one or more elements selected from the group vanadium, columbium, tantalum; the remainder substantially iron.

5. A process which comprises subjecting a material to be hydrogenated to the influence of hydrogen at high-hydrogen partial pressure and high temperature in a container composed of a steel alloy consisting of carbon 01; over 1%, over al from the group vanadium, columbium, tant um; the remainder substantially iron with sil n not over about 1.5% and a manganese con nt within the usual range for low alloy steels.

6. A process which comprises subjecting a material to be hydrogenated to the influence 01' hydrogen at high hydrogen partial pressure and high temperature in a container composed of a steel alloy consisting of carbon not over 1%; vanadium in an amount at least four times, greater than the carbon content and not over 5%; the remainder substantially iron with silicon not over about 1.5% and a manganese content within the usual range for low alloy steels.

FRIEDRICH KARL NAUMANN. 

